The present invention relates to a spike which is fixedly secured to the sole of golf shoes.
The prior art spikes made of a metal and comprising individual spike pins have often damaged the putting green. Particularly in recent years, an increase in the number of golf players has brought about serious injury on each lawn. Therefore, many golf courses now oblige players to wear the so-called xe2x80x98soft-spikesxe2x80x99 in order to protect the putting green. A body of the soft-spike is generally made of a metallic material, which includes a male-threaded shank as an attachment to a shoe-sole. The body of the soft-spike is formed integral with a base plate by injection molding. The base plate has a plurality of short lugs (see for example the Japanese Patent Publication No. 6-104081, or the Japanese Utility Model Publication No. 3027022).
The soft-spikes are inferior to the metal ones in ground-gripping force. In addition, an end portion of each soft-spike is deficient in abrasion-resistance and durability because its body is made of a plastics. Particularly, abraded spikes will give rise to unsatisfactory shots, so that golf players need to renew their spikes frequently, thus problematically causing them much labor and expense.
The present invention was made in view of the deficiency in the prior proposal. An object of the invention is therefore to provide a metal spike for golf shoes that excels in abrasion-resistance and durability. Another object of this invention is to provide a spike which can firmly engage the ground tightly and yet to prevent the putting green from being injured.
In order to achieve these objects, the spike for golf shoes proposed herein has a quench-hardened metal plate, an upper face of which is of a concave configuration to form a base plate of a washer-shape like a dish. A periphery of the base plate is made integral with a plurality of tooth-shaped lugs that are arranged at regular angular intervals and bent downwards. A central part of the base plate has an upright and fixable or fastenable columnar member having a male-threaded shank. The tooth-shaped lugs are tapered outwards relative to the base plate.
The base plate and the columnar member are separately manufactured, and the latter is caulked to firmly adjoin the former, enabling mass-production of the spike at a lowered cost. For this purpose, the following structure may be preferable.
Namely, a middle flange is formed integral with and disposed between the male threaded shank and a short end portion. A non-circular hole penetrating the central portion of the base plate has a serrated inner periphery so that the short columnar end portion inserted in the hole is then caulked to have its own outer serration in mesh with the serrated inner periphery. At the same time and as a result of such a caulking process, an end flange is formed at an extremity of the short columnar end portion. The end flange facing the middle flange and is of a shape corresponding thereto so that the non-circular hole""s periphery is sandwiched by and between the two flanges, whereby the fastenable columnar member is fixedly secured to the base plate.
Furthermore, it is possible to form an extra pin protruding downwards from the central part of the plate when the columnar end portion is caulked. In addition, pawls may be formed in the base plate by opening up the portions located around the base plate central portion, wherein each pawl extending in a circular direction is slanted in such a fashion that the base plate is prevented from loosening.